‘A skin lesion is a superficial growth or patch of the skin that does not resemble the area surrounding it.’ [1]
Skin lesions can look unattractive, or cause problems by rubbing against clothing. Most skin lesions are benign, but you should check with your doctor if you are worried that a lesion on your body may be cancerous. Cancerous lesions should be removed by a medical specialist.

Skin lesions include:Acne
Acne occurs when skin pores become blocked by oil, bacteria, and dirt, leading to infection. Severe acne can be painful and may result in scarring.

Boils (furuncles)
Boils are deep, localized and painful skin infections that develop on hair follicles. Also known as ‘furuncles’ or ‘abscesses’, they usually begin as small, sore, reddened bumps on the skin, later developing a soft, pale, pus-filled center.

Bullae
Bullae are fluid-filled sacs or lesions that appear when fluid is trapped under a thin layer of skin. Similar to blisters, bullae are larger.

Cherry Angioma
Cherry angiomas are small, bright red skin growths that are circular or oval in shape. They can grown on most areas of the body.Cysts
A cyst is a sac-like pocket of tissue that contains fluid, air, or other substances. Cysts can grow almost anywhere in the body or on the skin.

Erysipelas
Erysipelas is a bacterial infection that affects the skin’s upper layers and causes lesions. It most commonly affects the legs, but can also affect the face. It usually begins when the bacteria enter the skin by way of a scratch or other wound. A reddened area of skin develops and spreads rapidly. It may be accompanied by fever and headaches, and requires professional treatment.

Freckles
Freckles are discolored spots on the skin; clusters of concentrated melanin. Causes of freckles include genetics and exposure to the sun.

Keloids
Keloids are smooth, hard skin growths that sometimes form when scar tissue grows excessively. They are not harmful but may be large and unsightly.

Lentigines
A lentigo (plural: lentigines), as mentioned elsewhere in this book, is a spot on the skin that is darker (usually brown) than the surrounding skin. Lentigines are more common among people with fair skin.
Exposure to the sun is thought to be the major cause of lentigines. Lentigines most often appear on parts of the body that get the most sun, including the face and hands. Some lentigines may be caused by genetics (family history) or by medical procedures such as radiation therapy.

Lipomas
Lipomas are noncancerous growths of fatty tissue that develop just under the skin, typically appearing on the neck, shoulder, back, abdomen, arms, and thighs. They look like small, dome-shaped lumps.Moles
Moles occur when cells in the skin grow in a cluster instead of being spread throughout the skin. These cells are called melanocytes, and they manufacture the pigment that gives skin its natural color. Moles may darken after exposure to the sun, during the teen years, and during pregnancy.

Molluscum Contagiosum
Molluscum contagiosum is a skin infection that is caused by the molluscum virus. It produces round, firm, benign and painless bumps on the upper layers of the skin.

Nodules
A nodule is an abnormal growth that forms under the skin, often filled with inflamed tissue or fluid. These skin lesions are harmless but can be confused with cysts, tumors, and abscesses.

Pock Marks
Also known as varicella, chickenpox is a virus that often affects children. It is characterized by itchy, red blisters that appear all over the body. These can leave indentations called pock marks. Other causes of pock marks include acne scarring and smallpox.

Scars
Scars can result from injuries such as burns and cuts. They are areas of fibrous tissue (fibrosis) that replace the normal skin.

Sebaceous Cysts
Sebaceous cysts are common, non-cancerous skin cysts, often found on the face, neck, or torso. They look like small, smooth, painless lumps under the skin, and are not life-threatening but may be uncomfortable.

Seborrheic Keratosis
Seborrheic keratosis is a type of harmless skin growth that bears a resemblance to skin cancer. The growths may have a rough, wart-like surface and a waxy look. Their appearance can vary widely, from smooth to rough, from pale to dark. Their size generally ranges from 0.2 – 3 cm. They have well-defined borders and look as if they are simply glued onto the skin.
Seborrheic keratoses are more common in older people. Their cause is unknown, and they usually appear on the head, neck, or torso. Seborrheic keratoses are non-cancerous (benign) although sometimes they can resemble melanomas because of their irregular borders. In some cases, keratoses cause itching or irritation.
These skin lesions can be removed with surgery, laser, freezing, or scraping. Vitamin D3 ointment is also being tested as a treatment.

Skin Tags
Skin tags are small, harmless growths, usually the same color as the skin or darker. They hang off the skin like a tiny pouch, often growing on neck, breasts, groin, stomach, eyelids, and underarms.

Stretch Marks
Stretch marks or striae (singular: ‘stria’), as they are called in dermatology, are a form of discolored scarring on the skin. They are caused by tearing of the dermis. Over time stretch marks may diminish, but they will not disappear completely.
Stretch marks are usually the result of the skin being stretched quickly, due to swift growth, swift weight gain or pregnancy. They can also be associated with factors such as hormonal changes during puberty or hormone replacement therapy, or a rapid increase in muscle due to bodybuilding.

Warts
Warts are raised bumps on the skin caused by the human papillomavirus (HPV). They are generally not dangerous but are contagious and can be painful.